1. Technical Field
This invention relates to outriggers as used on certain types of wheeled vehicles such as fire engine ladder trucks employing movable extension ladders, booms or cranes, the vehicles being designed to travel under their own power along highways which limits their lateral dimensions. When set up for operation at a site the large extension ladders, booms, and the like are often extended laterally to the side of the vehicle and exert a moment on the vehicle that will tip over the vehicle or tilt the vehicle if no further lateral support is provided other than the wheels of the vehicle. To provide lateral stability to resist such tipping moment, it is common to use outrigger legs on one or both sides of the vehicle with each such leg employing telescoping housing with the housing permanently angled outwardly and downwardly or swung to such angled position about a pivot. The legs are telescoped downwardly from their housing into engagement with the ground outwardly of the wheels to provide stability. There are many occasions when such stability is not enough and the boom or ladder must therefore be lowered or the extension angle of the boom or ladder length reduced or the vehicle must be moved closer to the work area all to reduce the tipping moment to an acceptable level that can be handled by the existing outrigger structure. Further, to obtain whatever distance is obtained by the outrigger structure from the adjacent vehicle wheel line, the mechanisms are greatly restricted by the allowable beam or width of the vehicle as permitted by road traveling conditions or requirements.
2. Description of the Prior Art:
The prior art disclosing outrigger support systems is represented by U.S. Pat. Nos. 3,215,282 to Wiemann, et al, 3,276,603 to Noller and 3,985,036 to Decker, et al.
The disclosures of the Wiemann, et al and Noller patents relate to adjustable outriggers having telescopic legs. In the disclosures the inner leg members are manually pulled outwardly of the outer leg members and pins are inserted in aligned holes at the desired adjusted length. The leg assemblies are pivoted to the vehicles or implements on which they are mounted and are movable relative thereto by hydraulic or pneumatic means.
The Decker, et al disclosure relates to an outrigger system having outboard leg members which are pivotally mounted to inboard leg members. None of the prior art discloses the structure of the present outrigger support system and in particular the laterally movable extensions which substantially increase the outrigger support ability.